Something odd going on here
rm -r simply unlinks the data (including, of course, the directories themselves) from the directory tree. The data is still on disk if not organised in a friendly way; simply running od on the device sees it. Even if /dev is gone it should be visible if the drive is hooked up to another machine. If the data recovery company couldn't find any data then either they were not fit for purpose or something considerably stronger than rm hosed the drives.
Biting the hand that feeds IT
